Portable cooler



FIG. 1 is a front perspective view of the portable cooler of my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a right side view as viewed from the right side of FIG. 4; and,

FIG. 6 is a bottom view of the portable cooler of my new design. 

I claim the ornamental design for a portable cooler, as shown and described. 